1. Field of the Invention
The present invention relates to a probe card, and more particularly, to a probe card capable of adjusting the relative position between a probe on the probe card and a device under test (DUT).
2. Description of the Related Art
The probe card is manufactured according the specifications of the DUT such as pin count, pitch, pad size and the probe depth of the testing machine. To test the electrical property of the DUT, the probe of the probe card transmits the testing signal from the testing machine to the DUT and transmits the measured electrical parameters for analyzing the electrical property back to the testing machine.
FIG. 1 is a cross-sectional view of a probe card 10 according to the prior art. As shown in FIG. 1, the probe card 10 comprises a circuit board 12, a supporter 14 positioned on the circuit board 12, a plurality of probes 16 fixed on the supporter 14, and the conductive through hole 20 electrically connects to the probe 16 and a conductive wire 26. In order to prevent the lateral position of the probe 16 from shifting as the use time increases, the probe 16 is fixed firmly on the supporter 14 by an epoxy resin 24. When the testing is carried out, the probe card 10 is placed on a testing machine (not shown in the FIG. 1) and the probe 16 electrically contacts a signal pad 38 of a DUT 30 to transmit the testing signal for the electrical property parameter.
However, the prior art probe card possesses the following defects:
The conventional probe card 10 can only be applied to a specific DUT: because the conventional probe card 10 is customized according to the specifications of the DUT 30 and the testing machine and uses the epoxy resin 24 to fix the probe 16 on the circuit board 12, the probe card 10 can only be applied to the specific DUT as the manufacture processing of the probe card 10 is completed. If the DUT is designed with a new specification of probe arrangement and pitch, a new probe card conforming to the new specification must be manufactured, which greatly increases the testing cost.
The probe position lacks adjusting flexibility: the probe position of the conventional probe card 10 is fixed on the circuit board 12 by the epoxy resin 24 after the technique personnel of the probe card manufacturer completes the position tuning. If the transportation of the probe card 10 or the careless use results in the shifting of the horizontal position, users must send the probe card 10 back to the original manufacturer for calibration, i.e., the conventional probe card 10 lacks the flexibility for the user to perform adjustment.
The entire probe card should be discarded in case a single probe is damaged: the conventional probe card 10 uses the epoxy resin 24 to fix the probe on circuit board 12 according to the designed position. When one probe or several probes are damaged, a new probe card must be manufactured again. The overall probe position level will be seriously affected even if the probe replacement is carried out since the replacement needs to remove the epoxy resin 24. Consequently, the accuracy of the testing result is influenced.
The single-function testing can not meet the future application requirements: the conventional probe card 10 can only carry out the testing for a single function of the DUT, such as the testing of DC (Direct Current) electrical property or AC (Alternative Current) electrical property. Facing the demands of the future RF (Radio Frequency) devices, the probe card manufacturer attempts to incorporate the RF probe and the DC probe in a single probe card, wherein the RF probe and the DC probe remain fixed on the probe card by the epoxy resin. However, the probe card still cannot meet the required frequency for testing the RF device because of the difference between the material property of the RF probe, the DC probe and the epoxy resin. Therefore, the current electrical property testing of the RF device is still carried out by separating the DC parameter testing and the RF parameter testing, which increases the testing time by 2 to 3 times.